Question

In Young's double slit experiment, the fringe width is $\beta$. If the entire arrangement is placed in a liquid of refractive index $\mu$, the fringe width will become

• A. $\mu \beta$
• B. $\frac{\beta }{\mu }$
• C. $\frac{\beta }{\mu +1}$
• D. $\frac{\beta }{\mu -1}$

Answer 1

Answer: (B)

$\frac{\beta }{\mu }$

In a liquid of refractive index $\mu$ the wavelength of light becomes $\frac{\lambda }{\mu }$ given $\lambda$ is wavelength in vacuum

$\beta =\frac{\lambda D}{d}$

${\beta }_{\mu }=\frac{\lambda D}{\mu d}=\frac{\beta }{\mu }$

Answer. B